Mayor questions why reservoir not in use

Port Lincoln mayor Peter Davis has questioned whether a toxic chemical is the reason why the area's main reservoir is not being used.

The 11,000-megalitre Tod Reservoir has been decommissioned because SA Water says salinity is high.

But Mr Davis says he has been told the real reason is agricultural run-off of the farm chemical Simazine.

He says whatever the reason, SA Water is wasting a valuable resource and the reservoir should be restored.

"Given that there may be this toxic chemical Simazine in there which has come off farmers' paddocks for the last 50 years or whatever it is I don't know, ergo you can't use the water," he said.

"Well that is not what SA Water told myself (sic), they said quite categorically there would be insufficient water, well maybe the real reason is that there's Simazine in there."

SA Water says research has found high salinity, not harm from agricultural run-off.

It says water problems also include pathogens such as cryptosporidium, which can cause illness.

Mr Davis says the reservoir should be drained and refilled, but a SA Water regional manager, Rob Hughes, says that will not happen.

"It's simply not a feasible option. There are a number of complex issues associated with draining a reservoir - the environmental issues downstream, the exposure of the soil at the bottom of the reservoir plus the nature of the catchment is very variable and seasonal so it introduces some significant risks and unreliability about the water resource and how we'd fill the reservoir," he said.